A sampling of 18 unique types of techno-pop music has been hurled into space by a San Francisco-based research group, in search of an extraterrestrial audience.

If aliens are expecting Barry Manilow, they’ll be disappointed. But maybe — hopefully — they’ll join us in a high-tec duet.

That’s the vision of METI, or Messaging Extra Terrestrial Intelligence, which has partnered with the edgy Spanish electronic music festival Sonar to send some conversation-starters via radio signals — a silent and invisible pulse that’s the mathematical equivalent of “dance with us!” — to a planet orbiting a nearby star called GJ273b.

On Thursday, the team announced it transmitted on three successive days — Oct. 16, 17 and 18 — from the EISCAT 930 MHz transmitter in Tromsø, Norway.

Because the planet is 12 light-years away, it would take at least 24 years for a response to reach us, so our children and grandchildren must be listening carefully in the early 2040s.

“If we do get a reply, and understand it, it would be a beautiful and important thing to find out how differently other intelligences understand our universe,” said METI president Douglas Vakoch, former director of Interstellar Message Composition at the Search for Extraterrestrial Intelligence Institute in Mountain View, known as SETI.

It’s not the first time that we’ve reached out to sing hello.

In 1974, Puerto Rico’s Arecibo Observatory broadcast more than two minutes of radio waves into space. That signal, known as the Arecibo message, was our first effort to send noise to another solar system.

In the late 1970s, sounds of opera, rock ‘n roll, blues and classical music were etched into the grooves of “The Golden Record,” then sent into space aboard our Voyager spaceships. Like those LPs sitting in your basement, it’s likely the record will never be played.

In 2008, Doritos embarked upon an “out-of-this-world” advertising campaign, beaming an advertisement for its tortilla chips into a solar system 42 light years away. The 30-second video clip showed a tribe of Doritos escaping from a pack and sacrificing a chip to the God of Salsa.

Lest aliens hear this and conclude our pale blue dot lacks any form of intelligent life, METI and Sonar wanted to do something better.

They targeted a planet orbiting “Luyten’s Star,” or GJ273, a red dwarf in the constellation Canis Minor located about 12 light-years from our sun. It’s a quarter the mass of Earth’s sun and has 35 percent of its radius.

It was chosen as the target because it is the closest star with a known planet that is potentially habitable — and is visible from the Northern Hemisphere, which was important because the EISCAT transmitter is located in Norway, north of the Arctic Circle.

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The project commissioned music — 10 seconds each — from Barcelona’s Sonar festival, famed for its ambitious multimedia design work and electronica acts. Musicians came from diverse backgrounds and origins, such as French electronic music performer Jean-Michel Jarre, English spoken word artist Kate Tempest, electronic music duo Matmos and others.

The music was transmitted digitally — coded as 1s and 0s — as a WAV file.

“This is not a full appreciation of Bach,” said Vakoch. “It’s more symbolic. ET would be hard pressed to appreciate the musical nature of the files.”

To help, METI’s transmission included a mathematical and scientific tutorial that includes innovative features like a “cosmic clock,” letting extraterrestrials confirm our understanding of time. It also tells them when we’re expecting a reply.

“The reason we chose to focus on math and physics is because it provides a natural link to music,” Vakoch said.

Since the same message is sent on multiple days, the aliens can be assured that it’s real, and not just random interstellar noise.

In April, METI will turn the EISCAT transmitter into a musical instrument, sending 15 more melodies by transmitting pulses at a series of different radio frequencies that maintain the same sort of intervals between one another — like the intervals between musical notes.

Some oppose the effort, saying we shouldn’t draw attention from potentially hostile aliens. Others say we should wait until we’re better communicators — and, then, only send messages with international consultation.

“All such transmissions should come from humanity as a whole,” said Andrew Fraknoi, emeritus chair of the Astronomy Department at Foothill College, “and not from particular individuals or groups pursuing disparate aims — without worldwide discussions.”

“If all the inhabitants of the galaxy only listen, then our SETI experiments to eavesdrop on alien broadcasts will inevitably fail,” said Seth Shostak, senior astronomer at the SETI Institute.

“There are some who will complain that shouting to the skies might be dangerous. But only very advanced alien societies could travel here and possibly wreak havoc on our world. However, such sophisticated extraterrestrials will also be able to detect the landing radars at our airports. So it’s kind of silly to worry about experiments such as this,” he said.

“I say, on behalf of the Klingons, that I’d prefer to listen to some good music than to the empty whistle of SFO’s radar.”